Our invention relates to the field of copiers and more particularly plain paper copiers which employ a scanning exposure system, which are capable of making copies on copy paper of two different sizes and which are adapted for use with a collator.
There are known in the prior art copying machines which can selectively make copies on copy paper of different sizes from different supplies. Many such machines employ a scanning optical system in which a mirror is moved across the machine below a transparent platen on which the original is placed face down. In such machines, the length of scan is the length of the longest copy being made, whether or not one is actually making a copy which is shorter than the longest copy.
In most installations where, for example, letter-size and legal-size copies are being made, one or the other of the two sizes will be used with greater frequency. In such instances, one of the two cassettes with which the machine is provided is a high capacity cassette which may hold as many as 1,000 sheets of copy paper, while the other or auxiliary cassette holds only 250 sheets. Means is provided for manually selecting which of the two cassettes will be used. It often occurs that the machine user leaves the selecting member, such for example as a lever in position to feed sheets from the auxiliary cassette, whereas the next user is much more likely to wish to make a copy of the size of the sheet carried by the main cassette.
Many machines of the prior art presently are used with collators, which automatically separate copies being made into sets. Like the machines with which they are used, the collators are adapted to receive copies of different sizes. One form of collator known in the prior art is provided with a "back bar", which is adapted to arrest copies being fed into the bins of the collator. This back bar is, moreover, manually adjustable to the size of the copy being made, so that the stacks of copy sets formed in the collator are neat and uniform.